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Path: utzoo!utgpu!water!watnot!watmath!clyde!rutgers!lll-lcc!seismo!mimsy!chris
From: chris@mimsy.UUCP
Newsgroups: comp.lang.c,comp.bugs.4bsd
Subject: Re: Bad Pointer Declaration in 'scandir'
Message-ID: <6145@mimsy.UUCP>
Date: Sun, 5-Apr-87 07:55:50 EST
Article-I.D.: mimsy.6145
Posted: Sun Apr  5 07:55:50 1987
Date-Received: Sun, 5-Apr-87 21:47:25 EST
References: <2479@dalcs.UUCP> <5916@mimsy.UUCP> <2491@dalcs.UUCP> <1575@dg_rtp.UUCP>
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 40
Xref: utgpu comp.lang.c:1474 comp.bugs.4bsd:272

This is getting out of hand, but I cannot let my reputation get
tarnished here :-).

In article <1575@dg_rtp.UUCP> throopw@dg_rtp.UUCP (Wayne Throop) writes:
>... Unusual as it is for Chris to make a mistake, he has made a
>doozy here (though an easy doozy to make, so to type).

>In particular, the claim that *(*foo)[], which is a pointer to an array
>of pointers, should be replaced by ***foo, which is a pointer to a
>pointer (or an array of pointers) to a pointer (or an array of pointers)
>is WRONG, WRONG, WRONG!

I did not (or I hope I did not) make such a claim.  Rather, my
claim was that the type of `namelist' in scandir should have been
(struct direct ***): not (struct direct **[]), as it was in the
source and manual page; nor (struct direct *(*)[]), as was suggested
in the first article with this title.

So let us take a look at the top of scandir:

	scandir(dirname, namelist, select, dcomp)
		char *dirname;
		struct direct *(*namelist[]);
/* the parentheses in the line above are unnecessary */
		int (*select)(), (*dcomp)();
	{
		...

Lo!  Namelist is a *parameter*.  And what happens with array
declarations when they appear in parameter contexts?

And (not that it is now necessary), as a coup de grace (where are
the accents? there are no accents on my keyboard!), I quote from
the comment immediately preceding the code to scandir() itself:

	Returns the number of entries and a pointer to a list of
	pointers to struct direct (through namelist).
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7690)
UUCP:	seismo!mimsy!chris	ARPA/CSNet:	chris@mimsy.umd.edu